Dash-pot.



J. D. BURKHOLDER.

DASH POT.

APPLICATION FILED SEPT-24,1910.

Patented Mar. 27, 1917.

[N VE/V T OR WW A9.

UNITE STATES PATENT OFFICE.

JOHN D. BURKHOLDER, OF LANCASTER, PENNSYLVANIA, ASSIGNOR, BY MESNEASSIGN- OF TOLEDO, OHIO, A CORPORATION OF NEW MEETS, TO TOLEDO SCALECOMPANY,

JERSEY. M

DASH-POT.

To all whom it may concern. I

Be it known that I, JOHN D. BURKHOLDER,

a citizen of the United States of America,

Lancaster and State of Pennsylvania, have invented certain new anduseful Improvements in Dash-Pots, of which the following is aspecification.

This invention relates to dash pots and is in its main features ofgeneral application where suchdevices may be used. It is, however,especially adapted to controlling the vibration of scales and in theaccompanying drawingand specification it is specifically shownanddescribed as applied to a scale for the purpose of illustration. As willappear, my invention invloves an improved form of dasher or piston inwhich the damping eflect is controlled by'inanual adjustment and alsoautomatically controlled in accordance with theviolence or speed of themovement to which it is subjected. A further feature of my inventionconsists in the ready adjustment of the piston rod with reference to themovable part to which it is attached whereby the piston and rod maybereadily centered in the cylinder of the dash pot, Other features willappear from the detailed description and following claims. In thedrawings in which I have illustrated certain preferred forms of myinvention Figure 1 is a view partly in elevation and partly in verticalsection of a dash pot attached to the beam of a scale, a fragment 7 onlyof the beam bein shown; Fig. 2 is a cross section through t e piston onthe line 2, 2 of Fig. 1; Fig.3 is a view similar to Fig. 2 but showing amodification of one of the details; Fig. Ashoiws adetail of themodification shown in Fig. 3 and Fig. 5 shows a further modification ofthis detail; Fi 6 is a sectional view on the line 66 of Tig. 1; Figs. 7,8 and 9 are vertical sections showing modified forms of plungers; Fig.10 shows a slight modification of the valve shown in Fig. 7 Fig. 11 is aplan view of the spring shown in Fig. 8.

Referring more particularly to Figs. 1 and 2, Z represents the outer endof a scale "beam which may be of any well known type.

The cylinder of the dash pot is shownat A and is provided with a cover Ahaving an o ning F provided with internal screw reads for a purposewhich will appear.

The plunger, piston or dasher B is connect- I Specification of LettersPatent. Patented lu 27, 1917 Application filed September 24, 1910.Serial No. 583,676.

ed to the lever Z by-means of a piston rod cured in a horizontal bore inthe lever Z bymeans of a set screw 2 The disk K and rod F are perforatedand the perforations ahned to receive a screw pin K by which the rod issecured to the disk. The kerf or slot is ample to permit a rocking ofthe rod F and the trunnion K is not' only adjustable angularly withrelation to the lever in which it 'is mounted but is adjustablelongitudinally of the bore therein, whereby the piston rod and pistonmay be adjusted in all directions to secure proper alinement with thedash pot cylinder. In the particular modification shown in Fig. 1 thehollow piston head or dasher is formed in two sections, each of which iscomposed of an outwardly dished disk portion and a surroundingfiange,'the flanges of the two sections when secured'together meeting ina common plane. Between the dished disks is clamped a flexible resilientmember C, preferably of metal, and registering openings 1) are formedthrough the dasher sections and intermediate 'member near the centerthereof for the passage of fluid. Above these openings is mounted a bellE which may be reciprocated or adjusted toward and from the dasher andopenings by means of a sleeve E having internal threads engaging thethreads upon the rod F, though these threads may, if desired, be alsoformed upon the interior of the bell E. Upon its upper end the sleeve E"is provided with a hand nut F rigid therewith by which the sleeve may beturned to adjust the bell E. The hand out F 2 is provided with a packinggland F to pre-' vent the passage of the liquid from the dash potbetween the rod F and the sleeve. At

a point intermediate the ends and the bell to prevent oil escaping incase of the inver: sion of the dash pot. The upper and lower.

walls of the hollow piston are provided with openings B through whichthe liquid in" the dash pot surges as the piston is raised ings B andaround the flexible member C.

If, however,;the motion is more violent the flow of the liquid bends theflexible member back to a position in which it restricts the flowthrough the openings in the contiguous wall of the piston, and theamount of this flexure varies with the speed or violence of the movementof the piston so that the choking effect isaugmented as the speed of thepiston increases. For this reason the device is quickly brought to rest,no matter what the violence of the original movement. There is thusprovided not only means for manual control but means dependent for itshead B operation upon the violence of the movement to be controlled. InFig. 2 I have shown the piston head as provided with four openings Bshown in dotted lines and the flexible blade C is correspondingly shapedto co-act with all of the openings. It will be obvious that a greater orlesser number of openings can be employed without departing from myinvention. Thus,'in Figs. 4 and 5 I have shown a flexible plate adaptedto control two and three openings, respectively, or if desired the plateshown in Fig. 4 may be paired with another of the same kind and the pairused to control four openings as shown in Fig. 3. The plungerillustrated in Figs. 16 is the preferred form of my device, but a largevariety of modifications thereof may be adopted. For example, in Fig. 7I have shown a section of a dash pot cylinder with a piston therein, thelatter consisting of a single rigid member B connected to the piston rodand provided with a series of openings B for the passage of fluid.Within these openings are mounted valves C having disks at their endsconnected by suitable webs. Upon either side'of the pistonv head B ismounted a spring 0 clampe tothe piston head by nuts. Through the pistonhead and springs are formed registering passages b for the passage ofthe fluid, which passages are controlled by the bell E as in the deviceas shown in Fig. .1. The valves C are normally held in theirintermediate position by the springs 0, thus permitting a free passageof liquid through the openings in the When, however, a sudden movementis imparted to the piston, the resistance oifered by the liquid causesthe valves C to be shifted and the valve heads approaching the pistonhead 13 serve to restrict the flow of liquid therethrough. Fig.

- 8 shows yet another modification. In this construction the lower endof the valve rod F carries a pair of disks H, H held be tween the head Fand the lower end of the sleeve E, the upper end of which is providedwith a hand nut E13; which engages with a thread upon the upper end ofthe rod F. The disks H, H are spaced a distance apart and provided withinwardly of the disks H, H The intermediate disk is provided withopenings and loosely fits the interior of the cylinder, but the outsidedisks H and H are of somewhat smaller diameter whereby when the disksare in their normal position the liquid may readily pass around theouter disks and through the openings in the intermediate disk. When,

however, the piston is violently moved in' either direction the centraldisk is correspondingly shifted by the resistance of the liquid andchokes the passage around the adjacent disk. In Fig. 9 I have shown afurther modification. In this form of the device a rigid head B* isprovided with openings B and is flanked on either side by a spring metalplate 6 dished to provide a free passage around the periphery of thesame and through the ports in the head B As in the modification shown inFigs. 1 and 7 there are also provided ports I), the passage of liquidthrough which is controlled by the bell E. Obviously any violent motionof the piston is resisted by the liquid which causes one of the springplates to flatten out and check the flow through the openings in therigid head. It will be seen that in each modification I have providedthe pis- 'ton with a by-pass either therethrough or around the edgethereof or both, which passage may be controlled in part by hand and inpart automatically to throttle or check the rush of liquid therethroughor therearound. But in its broadest aspect my invention is not limitedto any specific form as will appear by the following claims.

I' claim 1. In a weighing machine, a movable member, a dash pot, saiddash pot having -a piston and a piston rod, a journal partiallyrotatable in the movable member, and means for connecting the journal tothe piston rod,

2. In a weighing machine, a movable member, a dash pot, said dash pothaving a piston and a piston rod, a journal partially rotatablein themovable member, a head on' the journal, said head having a slot therein,the piston rod having an extension lying in the slot of the head, andmeans for securing the piston rod to the head.

3. In a weighing machine, a movable member, a dash pot, said dash pothaving a piston and a piston rod, a journal partially rotatable in themovable member, means for directly connecting the journal to the pistonrod. and means in the movable member for holding the journal.

I. In a device of the class described, a cylinder. a piston movabletherein and provided with a plurality of openings, manually operatedmeans for controlling the flow through certain of the openings andspringpress'ed means operated by the flow of liquid for controlling theflow through other of the openings.

5. The combination of a movable member, a disk angularly adjustable withrelation thereto. a dash pot. a piston and piston rod, the lattereccentrically attached to the disk, and means for securing the disk inadjustable position.

6. In a device of the clans described. a movable member. a trunnionmounted therein and adjustable longitudinally and angularly withreference thereto. a disk carried by the trunnion and slotted to receivethe upper end of a piston rod, a dash pot, a piston and piston rodtherefor, the upper end of the latter entering the slot in the disk andpivoted therein.

T. In a device of the class described, a. cylinder. a pistonreciprocable therein and having two sets of openings. spring members forone set of openings normally maintained spaced from the latter butmovable toward the same under pressure and a member adapted to bemanually adjusted toward and from the other set of openings to controlthe flow of liquid therethrough.

8. In a device of the class described, a cylinder, :1 piston thereinprovided vvith a set of openings, a threaded piston rod, an obstructingmember E cooperating with the set of openings and threaded upon thepiston rod. a sleeve secured to said member surrounding the piston rodand extending outside the cylinder, and a stutting box on said sleeve.

9. In a device of the class described. a cylinder open at one end. aclosure for the open end of the cylinder having a threaded aperturetherein. the wall of this aperture being tapered. an apertured pistonmovable in the cylinder. :1 piston rod connected to the piston andextending through the aperture in said closure, a rotatable sleevesurrounding the piston rod. and an externally threaded plug surroundingsaid sleeve. the outer Wall of said plug being tapered to conform withthe wall of the aperture in said closure.

In testimony whereof I have hereunto atlixed my signature in thepresence of tvvo witnesses.

' JOHN D. BURKHOLDER.

Witnesses:

W. J. MIKGLE, ADAM DEILET.

